Process and composition for the immobilization of high alkaline radioactive and hazardous wastes in silicate-based glasses

ABSTRACT

The present invention provides processes to immobilize high alkaline radioactive and/or hazardous waste in a silicate-based glass, the waste containing one or more of radionuclides, hazardous elements, hazardous compounds, and/or other compounds. The invention also provides silicate-based glass compositions for use in immobilizing radioactive and/or hazardous waste.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 60/783,415 filed Mar. 20, 2006, which is incorporated herein byreference in its entirety.

BACKGROUND Field of the Invention

The present invention relates generally to treatment of high alkalineradioactive and hazardous wastes, and more particularly to processes forimmobilizing a waste containing one or more of radionuclides, hazardouselements, hazardous compounds, and other compounds present in the waste.

BACKGROUND OF THE INVENTION

The use of radioactive and hazardous materials in the world has led tothe accumulation of a significant amount of radioactive and hazardouswastes. There is an international consensus regarding the planneddisposal of these wastes by burying them in the ground in deepgeological repositories. At the present time, high-level radioactivewastes are being placed in long-term storage awaiting permanentdisposal. Once buried, with the passage of time, groundwater andhydrothermal solutions can make contact with the radionuclides,hazardous elements, or hazardous compounds contained in the wastes. As aresult, groundwater and hydrothermal solutions can facilitate theleaching of radionuclides, hazardous elements, and hazardous compoundsout of the wastes into the biosphere in which plants and animals live.In addition, even without the interference from groundwater andhydrothermal solutions, radionuclides, hazardous elements, or hazardouscompounds could possibly diffuse out of the wastes, resulting incontamination of the biosphere. Therefore, improper containment of thewastes can create a significant problem.

There are a number of existing processes that can potentially reduce theleaching and/or diffusion of radioactive and hazardous wastes. Theexisting processes, however, have various disadvantages. For example,cementation is commonly used to immobilize low-level andintermediate-level radioactive waste. This process is undesirablebecause a large volume of cement is required to immobilize a smallquantity of wastes vastly increasing the size of the disposal area.Furthermore, cement is highly susceptible to both leaching anddiffusion.

The most common method of handling high-level radioactive wastes isvitrification in borosilicate glass. Vitrification is currently beingused in a number of countries including France, the United States ofAmerica, Korea, Italy, Germany, the United Kingdom, Japan, Belgium,China, and Russia. Conventional vitrification processes, however, arelimited in the amount of waste that can be contained, and efforts toincrease waste loading capacity of borosilicate glasses or melts haveled to high crystallinity, increased rates of leaching, and increasedcorrosion of the melter, rendering the compositions unsuitable for usein conventional vitrification melters.

Thus, a need exists for improved vitrification processes andborosilicate glass-like compositions that achieve higher waste loadingwithout the above-mentioned disadvantages on use of the processes andcompositions with conventional vitrification melters.

Although low-level radioactive waste is not generally vitrified, in theU.S., for example, low-level radioactive waste with high sodium contentis planned to be vitrified at the Waste Treatment Plant in Richland,Washington State. Sodium is a high active alkaline element, which, whenimmobilized in borosilicate glass in high concentrations, causes lack ofdurability of the glass. Much of the low-level radioactive waste foundin the U.S. radioactive waste sites, such as Envelope A of the HanfordLAW (the majority of the LAW to be processed at the Hanford WasteTreatment Plant) is characterized by high sodium concentrations. Thecurrently planned sodium waste loading for these low-level radioactivewastes is between about 20-23 weight percent, although the actualacceptable waste as reported in industry is between about 18-20 weightpercent. When greater amounts of sodium are introduced into the finalglass, it becomes unstable and is unable to satisfy the waste formacceptance criteria and the processing requirements for a vitrificationmelter.

In order to increase the concentration of sodium in the final glass, onemust create a composition that will incorporate this sodium yet satisfythe waste form acceptance criteria and the processing requirements for avitrification melter. The waste form acceptance criteria (durability andleach resistance of the glass) are tested by Vapor Hydration Test (VHT),Product Consistency Test (PCT) and Toxicity Characteristic LeachProcedure (TCLP). The processing requirements include viscosity,specific electrical conductivity and crystallization.

Thus, a need exists for improved vitrification processes andborosilicate glass-like compositions that achieve higher sodium wasteloading without the above-mentioned disadvantages on use of theprocesses and compositions with conventional vitrification melters.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a process for immobilizing high alkalineradioactive and/or hazardous waste in silicate-based glasses, andcompositions for use in the processes. In one aspect of the presentinvention, a process is provided for immobilizing high alkaline wastecomprising combining the waste with glass-forming components inparticular proportions, melting the mixture to form a glass integratingthe waste with properties suitable for waste vitrification melters,pouring the melted glass with integrated waste into a receptivecanister, and solidifying the melted glass with the integrated waste bycooling. In addition to use of standard waste vitrification melters, thewaste may be vitrified in an “in-container” or “in-can” process whicheliminates the necessity of pouring the melted glass with integratedwaste into a receptive canister. The ratio between the rock-formingcomponents of the glass formed (i.e. SiO₂, Al₂O₃, alkaline earth oxidesand alkaline oxides) approximates the ratio between the main componentsof natural high alkaline ultrabasic rock. This glass is especiallysuitable for immobilizing high alkaline wastes.

In another aspect of the present invention, a process is provided forimmobilizing high alkaline waste comprising combining the waste withglass-forming components in particular proportions, melting the mixtureat a temperature of up to about 1150° C., to form a low viscosity meltedglass having a viscosity of about 20 to about 100 poise, with propertiessuch as specific electrical conductivity ranging between about 0.1 Ω-1cm⁻¹ to about 0.7 Ω-1 cm⁻¹, suitable for waste vitrification melters,pouring the melted glass with integrated waste into a receptivecanister, and solidifying the melted glass with integrated waste bycooling. At present, the melting temperature used for vitrification inthe U.S. is 1150° C. It is known that higher melting temperaturesincrease the processing rates for vitrification. Although the processesand glasses of the present invention have desirable advantages atmelting temperatures of up to about 1150° C., higher and lowertemperatures are also suitable and advantageous. In addition to use instandard waste vitrification melters, the waste may be vitrified in an“in-container” or “in-can” vitrification process which eliminates thenecessity of pouring the melted glass with integrated waste into areceptive canister. In preferred embodiments of the present invention,the ratio between the rock-forming components of the glass formedapproximates the ratio between the main components of natural highalkaline ultrabasic rock.

In a further aspect of the present invention, a process is provided forthe immobilization of high alkaline radioactive and/or hazardous wastein a silicate-based glass. In the process, a silicate-based glass isformed in which the ratio between the rock-forming components of theglass formed approximates the ratio between the main components ofnatural high alkaline ultrabasic rock. The silicate-based glass formedis used as an immobilizing matrix for radioactive and hazardous waste.The process involves melting together glass-forming and waste componentsconsisting essentially of three groups of oxides: (R₂O+RO), R₂O₃, and(RO₂+R₂O₅). The ratio between the rock-forming components of the glassformed is about (1.6-2.2):(1):(2-3) in weight percent, where the(R₂O+RO) consists primarily of Na₂O, the R₂O₃ consists primarily ofAl₂O₃, and the (RO₂+R₂O₅) consists primarily of SiO₂. In addition,higher amounts of B₂O₃ and other flux components are used than in othersilicate-based glasses for immobilizing high-alkaline waste, in order toreduce the melting temperature of the ultrabasic rock.

In yet another aspect of the present invention, a silicate-based glasscomposition is provided for the immobilization of high alkalineradioactive and/or hazardous waste. The ratio between the rock-formingcomponents of the glass formed approximates the ratio between the maincomponents of natural high alkaline ultrabasic rock. The silicate-basedglass consists essentially of three groups of oxides: (R₂O+RO), R₂O₃,and (RO₂+R₂O₅). The rock-forming components of this glass has a ratio ofabout (1.6-2.2):(1):(2-3) in weight percent, where the (R₂O+RO) consistsprimarily of Na₂O, the R₂O₃ consists primarily of Al₂O₃, and the(RO₂+R₂O₅) consists primarily of SiO₂. In addition, higher amounts ofB₂O₃ and other flux components are used than in other silicate-basedglasses for immobilizing high-alkaline waste, in order to reduce themelting temperature of the ultrabasic rock.

The glass formed by these processes, and according to thesecompositions, incorporates a substantially higher percentage of highalkaline waste than previously practiced, while at the same timesatisfying both the processing requirements (including viscosity,specific electrical conductivity and crystallinity) and waste formacceptance criteria (including durability and leach resistance of theglass, tested by Vapor Hydration Test (VHT), Product Consistency Test(PCT) and Toxicity Characteristic Leach Test Procedure (TCLP)) forglasses produced in waste vitrification melters. Additional advantagesand features of the present invention will be apparent from thefollowing detailed description and examples which illustrate preferredembodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a scanning electron micrograph depicting the results of aone-week Vapor Hydration Test for a glass of the present invention.

FIG. 2 is a scanning electron micrograph depicting the results of atwo-week Vapor Hydration Test for a glass of the present invention.

FIG. 3 is a scanning electron micrograph depicting the results of afour-week Vapor Hydration Test for a glass of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the presently preferredembodiments of the invention, which, together with the followingexamples, serve to explain the principles of the invention. Theseembodiments are described in sufficient detail to enable those skilledin the art to practice the invention, and it is to be understood thatother embodiments may be utilized, and that structural, chemical, andphysical changes may be made without departing from the spirit and scopeof the present invention.

DEFINITIONS

The term “waste” includes waste materials, such as fission products,which contain radionuclides, hazardous elements, radioactive compounds,hazardous compounds, and/or other components present in the waste. Wastemixtures can include, for example, the following elements and theircompounds: Fe, Na, S, P, Cr, Al, Mn, Ni, Na, Zr, K, Cs, Ru, Sr, Ba, Tc,Rh, Mg, I, lanthanides, actinides (for example, Th, U, Pu, Np, Am, Cm,and Ce), and their compounds, and other components of radioactive andhazardous waste. The waste may also include noble metals and volatilecomponents such as H₂O and/or CO₂. Not all of these elements and theircompounds, if separated, are hazardous.

The term “radionuclide” includes any nuclide that emits radiation,including one or more of alpha, beta, and gamma emissions. The term“nuclide” includes an atomic species in which all atoms have the sameatomic number and mass number. However, processes in which mixtures ofdifferent radionuclides are immobilized are specifically included withinthe scope of the present invention. Examples of radionuclides are Sr andCs, and actinides and lanthanides, such as thorium and uranium.

The term “radioactive waste” includes three levels of radioactive wastesclassified as follows:

1. “Low-level radioactive wastes” (LLW) and “Low-activity radioactivewastes” (LAW) are generated primarily from hospitals, laboratories, andthe industrial sector. Low-level radioactive wastes are also generatedwhen constituents are removed from high-level radioactive wastes inorder to concentrate high-level radioactive wastes. Low-levelradioactive wastes represent about 90% by volume but only about onepercent by radioactivity of all radioactive wastes in the world.

2. “Intermediate-level radioactive wastes” (ILW) comprise resins,chemical sludge, and nuclear reactor components. Intermediate-levelradioactive wastes represent about seven percent by volume and aboutfour percent by radioactivity of all radioactive wastes in the world.

3. “High-level radioactive wastes” (HLW) comprise spent nuclear reactorfuel (spent fuel) and other high-level radioactive wastes generatedprincipally from reprocessing the spent fuel and from nuclear weaponsdevelopment. High-level radioactive wastes represent only about threepercent by volume but about 95% by radioactivity of all radioactivewastes in the world.

The term “element” used in the context of radioactive or hazardouselements includes an atomic element of the periodic table. The term“compound” used in the context of hazardous or radioactive compoundsincludes a substance composed of two or more elements.

The term “hazardous wastes” is defined in the EPA Environmental Glossaryas any waste or combination of wastes which pose a substantial presentor potential hazard to human health or living organisms because suchwastes are non-degradable or persistent in nature or because they can bebiologically magnified, or because they can be lethal, or because theymay otherwise cause or tend to cause detrimental cumulative effects.

Because many of the compounds of waste mixtures are converted to oxidesin a vitrification process, the mixtures are commonly referred to interms of their “waste oxide” content. The term “waste oxide loading”,“loading of waste oxides”, “waste loading”, or “loading of waste” refersto the weight percentage of the waste mixture (once it is thermallyconverted to oxides in a vitrification process and which can includenon-hazardous components) in the final product of a waste immobilizingprocess. As used herein, the abbreviation “wt %” means weight percent.

As used herein, a “natural high alkaline ultrabasic rock” is determinedby the ratio in weight percent between (a) the sum of monovalent cationoxides (R₂O) and divalent cation oxides (RO) which are network modifyingcomponents, (b) trivalent cation oxides (R₂O₃) which are network formingcomponents, and (c) the sum of tetravalent cation oxides (RO₂) andpentavalent cation oxides (R₂O₅), which are also network formingcomponents. A shorthand manner of depicting or referring to this ratioused herein is (R₂O+RO):R₂O₃:(RO₂+R₂O₅). This ratio for natural highalkaline ultrabasic rock is about (1.6-2.2):(1):(2-3) in weight percent.

As used herein, “R₂O” refers to a monovalent cation oxide including, butnot limited to Li₂O, Na₂O and K₂O; “RO” refers to a divalent cationoxide including, but not limited to CaO, MgO and SrO; “R₂O₃” refers to atrivalent cation oxide including, but not limited to Al₂O₃ and Fe₂O₃;“RO₂” refers to a tetravalent cation oxide including, but not limited toSiO₂ and ZrO₂; and “R₂O₅” refers to a pentavalent cation oxideincluding, but not limited to P₂O₅.

The term “rock-forming components” includes primarily SiO₂, Al₂O₃, ZrO₂,alkaline earth oxides and alkaline oxides. The term “glass-formingcomponents” includes primarily SiO₂, Al₂O₃, ZrO₂, B₂O₃, P₂O₅, alkalineearth oxides and alkaline oxides; glass stabilizers including, but notlimited to, ZrO₂ and TiO₂; and fluxes such as Li₂O, F, B₂O₃ and P₂O₅(B₂O₃ and P₂O₅ can act both as glass-forming component and as fluxes).The term “flux components” includes primarily B₂O₃, P₂O₅, and F.

The term “silicate-based glasses” includes, but is not limited to,different types of silicate-based glasses such as borosilicate glass,phosphorus-silicate glass, titanium-silicate glass andzirconium-silicate glass. Although the preferred embodiments discussedherein refer to borosilicate glass, it is understood that the presentinvention is not limited to borosilicate glasses, but includes the useof other silicate-based glasses as the immobilizing matrix.

DESCRIPTION

The present invention is directed to an improved glass composition thatis designed to be as similar as possible to natural rock which isstable, i.e., can incorporate waste (including high alkaline waste) andstill satisfy the waste form acceptance criteria and the processingrequirements for a vitrification melter. There are four main types ofnatural rock:granite, andesite, basalt and ultrabasic. What primarilydifferentiates between them is the concentration of the network formingcomponents SiO₂ and Al₂O₃. Table 1 shows the average concentrations ofthese oxides in each type of rock. TABLE 1 Average Concentrations ofSiO₂ and Al₂O₃ in the Four Main Types of Natural Rock (in weightpercent)* Granite Andesite Basalt Ultrabasic SiO₂ 71 57 49 39 Al₂O₃ 1415 15 17*Taylor S. R. and McLennan A. H. The Continental Crust: Its Compositionand Evolution (Blackwell, 1985 xv)

As can be seen from Table 1, the SiO₂ concentration in ultrabasic rockis less than that found in the other types of rock, and the Al₂O₃concentration in ultrabasic rock is greater than that found in the othertypes of rock. This relatively higher concentration of Al₂O₃ inultrabasic rock allows the incorporation of higher amounts of alkalinesthan in the other three types of rock, because the Al in thealuminasilicates bonds with the alkalines and forms strong structuralunits.

A natural high alkaline ultrabasic rock is determined by the ratio inweight percent between (a) the sum of monovalent cation oxides (R₂O) anddivalent cation oxides (RO) which are network modifying components, (b)trivalent cation oxides (R₂O₃) which are network forming components, and(c) the sum of tetravalent cation oxides (RO₂) and pentavalent cationoxides (R₂O₅), which are also network forming components. A shorthandmanner of depicting or referring to this ratio used herein is(R₂O+RO):R₂O₃:(RO₂+R₂O₅). The (R₂O+RO):R₂O₃:(RO₂O₅) ratio for naturalhigh alkaline ultrabasic rock is about (1.6-2.2):(1):(2-3) in weightpercent.

In a first preferred embodiment of the present invention, asilicate-based glass is produced having a (R₂O+RO):R₂O₃:(RO₂+R₂O₅) ratiobetween the rock-forming components of the glass formed of(1.6-2.2):(1):(2-3) in weight percent. This ratio approximates the ratiobetween the main components of natural high alkaline ultrabasic rock.

In a second preferred embodiment of the present invention, asilicate-based glass is produced in which the (R₂O+RO):R₂O₃:(RO₂+R₂O₅)ratio is (1.6-2.2):(1):(2-3) in weight percent, and in which the(R₂O+RO) consists primarily of greater than about 23 weight percentNa₂O, the R₂O₃ consists primarily of between about 13 and 20 weightpercent Al₂O₃, and the (RO₂+R₂O₅) consists primarily of between about 30and 48 weight percent SiO₂. This (1.6-2.2):(1):(2-3) ratio is similar tothat of the ratio between the main components of natural high alkalineultrabasic rock.

The glass of this embodiment is substantially more stable than (1)silicate-based glasses currently produced for immobilizing highalkalines which do not have a (1.6-2.2):(1):(2-3) ratio between theirrock-forming components, or (2) silicate-based glasses for immobilizinghigh alkalines which have a (1.6-2.2):(1):(2-3) ratio between theirrock-forming components but which do not contain greater than about 23weight percent Na₂O, between about 13 and 20 weight percent Al₂O₃, andbetween about 30 and 48 weight percent SiO₂.

In a third preferred embodiment of the present invention, asilicate-based glass is produced in which the (R₂O+RO):R₂O₃:(RO₂+R₂O₅)ratio is (1.6-2.2):(1):(2-3) in weight percent, and in which the(R₂O+RO) consists primarily of greater than about 23, 24, 25, 26, 27, or28 weight percent Na₂O, the R₂O₃ consists primarily of between, e.g.,about 15-20 weight percent Al₂O₃, and the (RO₂+R₂O₅) consists primarilyof between about 30 and 48 weight percent SiO₂. This (1.6-2.2):(1):(2-3)ratio is similar to that of the ratio between the main components ofnatural high alkaline ultrabasic rock.

In a fourth preferred embodiment of the present invention, B₂O₃ andother flux components, such as P₂O₅, and F, which, in total, rangebetween about 9 and 15 weight percent are added to a glass of the priorembodiments. (Although Li₂O is used as a flux component as well, it isan alkaline oxide and therefore will not be added in a high-alkalinewaste because it will reduce the amount of alkaline waste that can beimmobilized). The B₂O₃ has 2 functions. It behaves as a glass-formingcomponent, preventing phase separation, in contrast to P₂O₅ or F, which,if used in amounts greater than approximately 5 weight percent, willcause phase separation. (Ultrabasic rock cannot be vitrified by itselfwithout the addition of glass-forming components such as B₂O₃). Inaddition to being a glass-forming component, B₂O₃ plays the role of aflux which decreases the melting point of the total composition,producing borosilicate glass which is required for use in conventionalvitrification melters. Our concentration of B₂O₃ and other fluxcomponents, which, in total range between about 9 and 15 weight percent,is substantially higher than the concentration of B₂O₃ and other fluxcomponents that is found in other borosilicate glasses which immobilizehigh-alkaline waste.

The B₂O₃ and other flux components are not rock-forming components, soalthough the ratio of the components of the final borosilicate glass isabout (1):(1):(1), the (R₂O+RO):R₂O₃:(RO₂+R₂O₅) ratio of therock-forming components of the glass (i.e. all of the componentsexcluding B₂O₃ and other flux components) remains about(1.6-2.2):(1):(2-3). This ratio between the rock-forming components ofthe glass is what is essential in that it is similar to the ratiobetween the main components of ultrabasic rock, and thus gives theborosilicate glass of the preferred embodiment the stability that isinherent in ultrabasic rock. The B₂O₃ that is added (thus producingborosilicate glass) is a non-coherent oxide for igneous rocks such asultrabasic rocks.

The advantage of the present invention is two-fold: firstly, it enableshigher waste loadings than have been previously achieved usingborosilicate glass in existing vitrification systems, while alsosatisfying processing and product quality requirements for wastevitrification (i.e., viscosity, specific electrical conductivity andchemical durability). See, for example, U.S. DOE/RW Waste AcceptanceSystem Requirements Document (WASRD), and Glass FormulationsforImmobilizing Hanford Low-Activity Wastes, D-S. Kim et al., WasteManagement '06 Conference, Feb. 26-Mar. 2, 2006, Tucson, Ariz., forprocessing and product quality requirements in the U.S. Secondly, itenables the achievement of these high waste loadings according to analgorithm, thus minimizing empirical trial and error. Both of theseadvantages render this invention commercially valuable.

It must be emphasized that the processes and glasses of the presentinvention are suitable for use in conventional melters and is alsosuitable for use in supplemental vitrification technologies, such as butnot exclusively, AMEC Earth and Environmental Inc.'s “BulkVitrification,” which is an “in-container” vitrification technology.

For example, when the glasses of the preferred embodiment are comparedto AMEC Earth and Environmental Inc.'s AMBG-13 glass (the glasscomposition produced by Pacific Northwest National Laboratory for AMEC,and determined to be the most suitable and selected as the baselinecomposition to test AMEC's Bulk Vitrification process as a supplementaltreatment technology for vitrifying Hanford Waste Treatment Plant's highsodium low activity radioactive waste), we see that the ratio between(R₂O+RO), R₂O₃, and (RO₂+R₂O₅) in weight percent for the rock-formingcomponents of the AMBG-13 glass is (1.24):(1):(2.41). This AMBG-13 glasshas a Na₂O loading of 20 weight percent, 9.89 weight percent Al₂O₃, and42.55 weight percent SiO₂. The flux components of the AMBG-13 glassinclude 5 weight percent B₂O₃, 0.07 weight percent F and 0.6 weightpercent P₂O₅. See Glass Formulationsfor Immobilizing HanfordLow-Activity Wastes, D-S. Kim et al., Waste Management '06 Conference,Feb. 26-Mar. 2, 2006, Tucson, Ariz.

Using the same waste simulant recipe as the AMBG-13 glass, applicationof the teachings of the present invention produced a borosilicate glasswith a Na₂O loading of 28 weight percent while also satisfyingprocessing and product quality requirements for waste vitrification(i.e., viscosity, specific electrical conductivity and chemicaldurability). This success in producing higher sodium waste loading isdue to the approximate (1.6-2.2):(1):(2-3) ratio between the (R₂O+RO),R₂O₃, and (RO₂+R₂O₅) rock-forming components of the glass of the presentinvention, which is maintained primarily due to greater than about 23weight percent Na₂O, between about 13 and 20 weight percent Al₂O₃, andbetween about 30 and 48 weight percent SiO₂.

Specifically, in the resultant glass, the (R₂O+RO) consists primarily of28 wt % Na₂O, the R₂O₃ consists primarily of 16 wt % Al₂O₃, and the(RO₂+R₂O₅) consists primarily of 36 wt % SiO₂ and 5 wt % ZrO₂. (Thetotal wt % of these main components is 85% and not 100% because 14 wt %B₂O₃ and several minor components of the waste are not included. Asmentioned above, the B₂O₃ is not included since it is a non-coherentoxide for igneous rocks such as ultrabasic rocks, and therefore behavesas a glass-forming component and not as a rock-forming component). Theconcentration of B₂O₃ and other flux components in this glass isapproximately 14.77 weight percent. In combination, the concentrationsof three of these major rock-forming components (Na₂O, Al₂O₃ and SiO₂)and the relatively high concentration of B₂O₃ and other flux components,are substantially different from their concentrations in currentlyproduced borosilicate glasses that immobilize high alkaline wastes.

As mentioned above, the preferred glasses of the present invention usegreater than about 23 weight percent Na₂O, between about 13 weightpercent and 20 weight percent Al₂O₃, between about 30 weight percent andabout 48 weight percent SiO₂, and in total between about 9 weightpercent and 15 weight percent B₂O₃ and other flux components. The highconcentrations of Na₂O and Al₂O₃ (relatively higher than theconcentrations generally used to produce borosilicate glassesimmobilizing high alkaline wastes), and relatively low concentration ofSiO₂ in the preferred glasses of the present invention allow maintenanceof the approximate (1.6-2.2):(1):(2-3) ratio in weight percent of therock-forming components. The relatively high concentration of B₂O₃ andother flux components decreases the melting point of the totalcomposition.

While known high-alkaline glasses may have individual components withinthe preferred ranges, no known glass contains the combination of each ofthese four components (Na₂O, Al₂O₃, SiO₂, and B₂O₃) in the preferredranges and an overall ratio between the rock-forming components thatapproximates that of natural high alkaline ultrabasic rock that is foundin the silicate-based glasses of the present invention.

For example, a known target glass evaluated during a recent performanceenhancement study initiated by the U.S. Department of Energy for Hanfordlow-activity waste (LAWA 187; glass formulated for Hanford's Envelope A,AN-105 LAW) has a Na₂O loading of 23 weight percent, 10.57 weightpercent Al₂O₃ and 34.8 weight percent SiO₂, and a total concentration ofB₂O₃ and other flux components of 12.77 weight percent. See PerformanceEnhancements to the Hanford Waste Treatment and Immobilization PlantLow-Activity Waste Vitrification System, Hamel et al., Waste Management'06 Conference, Feb. 26-Mar. 2, 2006, Tucson, Ariz. The ratio between(R₂O+RO), R₂O₃, and (RO₂+R₂O₅) in weight percent for the rock-formingcomponents of the LAWA 187 glass, however, is (4.45):(1):(9.96).

Likewise, in comparing over 1,900 glass compositions that wereformulated for Hanford wastes, none had both a (R₂O+RO), R₂O₃, and(RO₂+R₂O₅) ratio between the rock-forming components of their glass of(1.6-2.2):(1):(2-3) and a combination of concentrations of Na₂O, Al₂O₃,SiO₂ and B₂O₃ and other flux components within the ranges cited in thepreferred embodiments. See: Database and Interim Glass Property Modelsfor Hanford HLW and LAW Glasses (Vienna et al. 2002); PerformanceEnhancements to the Hanford Waste Treatment and Imnmobilization PlantLow-Activity Waste Vitrification System, Hamel et al., Waste Management'06 Conference, Feb. 26-Mar. 2, 2006, Tucson, Ariz.

Application of the teachings of the present invention to a specificproblem or environment is within the capabilities of one having ordinaryskill in the art in light of the teachings contained herein. Examples ofthe products and processes of the present invention appear in thefollowing examples.

EXAMPLE 1 Vitrifying Hanford Tank 241-S-109 Low-Active Waste (LAW)Simulant with 28 Weight Percent Na₂O Loading

1. The Hanford Tank 241-S-109 LAW waste composition from Column A wasused according to the amounts in Column B. Column C shows the amount (inweight percent) of the components in the target final glass product witha 28 weight percent Na₂O loading. C E B 28% Na₂O D Final A Waste LoadingAdditives Glass Components (wt %) (wt %) (wt %) (wt %) Al₂O₃ 1.37930.386 15.614 16.0 B₂O₃ 0 0 14.0 14.0 CaO 0.0395 0.011 0 0.011 Cl 0.15470.043 0 0.043 Cr₂O₃ 0.7008 0.196 0 0.196 F 0.0623 0.017 0.083 0.1 Fe₂O₃0.2219 0.062 0 0.062 K₂O 0.1216 0.034 0 0.034 Na₂O 94.9222 28.0 0 28.0P₂O₅ 2.3903 0.669 0 0.669 SiO₂ 0 0 36.0 36.0 SO₃ 0.7055 0.197 0 0.197ZrO₂ 0 0 5.0 5.0

2. Glass-forming components according to the amounts in Column D wereadded to the 241-S-109 waste composition, producing the final glasscomposition shown in Column E. The exact amounts of glass-formingcomponents used were calculated together with the 241-S-109 wastecomponents, so that the total amount of the components would achieve aratio of (R₂O+RO): R₂O₃: (RO₂+R₂O₅) in weight percent within the rangeof about (1.6-2.2):(1):(2-3). The ratio achieved was approximately(1.73):(1):(2.56).

3. The mixture of step 1 and step 2 was stirred together for 1 hour atambient temperature, producing an aqueous suspension.

4. The product of step 3 was then dried at 150° C. for 3 hours in alaboratory oven.

5. The product of step 4 was then crushed and sieved through a 420micron mesh, and then melted at 1150° C. for 2.5 hours in a mufflefurnace.

6. The product of step 5 was then poured into a slab of carbon in whichslots of 15 mm×15 mm×25 mm were carved. Other molds of differingmaterials (e.g., platinum, stainless steel, carbon, mullite, etc.) anddiffering sizes may be used. This was then cooled in the muffle furnacefor a minimum of 15 hours, according to various cooling regimens, toambient temperature.

7. The resultant glass was then tested to determine the suitability ofthis composition for processing using liquid-fed ceramic melter (LFCM)technology. The results of six tests demonstrated that the compositionwas suitable for processing using LFCM technology:

-   -   (a) Vapor Hydration Test (VHT) results (see Scanning Electron        -   Microscopy (SEM) photos in FIGS. 1-3):        -   1 week: 9.105 g/m²/day (FIG. 1)        -   2 weeks: 16.203 g/m²/day (FIG. 2)        -   4 weeks: 17.83 g/m²/day (FIG. 3)        -   (These results are the average results taken from 4 VHT            tests conducted on 3 separate batches prepared with the same            glass composition)    -   (b) Viscosity: Ranges from 38.3 poise at 1150° C. to 382 poise        at 950° C.    -   (c) Specific Electrical Conductivity: Ranges from 0.48 Ω⁻¹ cm⁻¹        at 1150° C. to 0.26 Ω⁻¹ cm⁻¹ at 950° C.    -   (d) Product Consistency Test (PCT) results (g/m²/d):        Na—2.72×10⁻¹; B—4.03×10⁻¹; Si—2.27×10⁻².    -   (e) Toxicity Characteristic Leaching Procedure (TCLP) results        (mg/L): Cr—1.8    -   (f) Secondary Phase Identification: No crystals were visible        using X-ray diffraction.

EXAMPLE 2 Vitrifying Hanford Tank AN-105 Low-Active Waste (LAW) Simulantwith 28 Weight Percent Na₂O Loading

1. The Hanford Tank AN-105 LAW waste composition from Column A was usedaccording to the amounts in Column B. Column C shows the amount (inweight percent) of the components in the target final glass product witha 28 weight percent Na₂O loading. C E B 28% Na₂O D Final A Waste LoadingAdditives Glass Components (wt %) (wt %) (wt %) (wt %) Al₂O₃ 17.3476.432 9.567 16 B₂O₃ 0.075 0.027 11.972 12 Cr₂O₃ 0.065 0.024 0 0.024 K₂O1.667 0.618 0 0.618 Na₂O 75.508 27.998 0 28 SiO₂ 0.101 0.037 35.962 36ZrO₂ 0 0 5 5 Cl 2.101 0.779 0 0.779 F 0.009 0.003 0 0.003 P₂O₅ 0 0 0.60.6 SO₃ 2.626 0.973 0 0.973

2. Glass-forming components according to the amounts in Column D wereadded to the AN-105 waste composition, producing the final glasscomposition shown in Column E. The exact amounts of glass-formingcomponents used were calculated together with the AN-105 wastecomponents, so that the total amount of the components would achieve aratio of (R₂O+RO):R₂O₃:(RO₂+R₂O₅) in weight percent within the range ofabout (1.6-2.2):(1):(2-3). The ratio achieved was approximately(1.78):(1):(2.59).

3. The mixture of step 1 and step 2 was stirred together for 1 hour atambient temperature, producing an aqueous suspension.

4. The product of step 3 was then dried at 150° C. for 3 hours in alaboratory oven.

5. The product of step 4 was then crushed and sieved through a 420micron mesh, and then melted at 1150° C. for 2.5 hours in a mufflefurnace.

6. The product of step 5 was then poured into a slab of carbon in whichslots of 15 mm×15 mm×25 mm were carved. Other molds of differingmaterials (e.g., platinum, stainless steel, carbon, mullite, etc.) anddiffering sizes could be used. This was then cooled in the mufflefurnace for a minimum of 15 hours to ambient temperature.

Since the final glass composition is very similar to the glasscomposition in Example 1, the physical-chemical properties (VHT, PCT,TCLP, viscosity, specific electrical conductivity, secondary phaseidentification) are expected to be the same as in Example 1.

The foregoing disclosure of the preferred embodiments of the presentinvention has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Many variations andmodifications of the embodiments described herein will be apparent toone of ordinary skill in the art in light of the above disclosure. Thescope of the invention is to be defined only by the claims appendedhereto, and by their equivalents.

Further, in describing representative embodiments of the presentinvention, the specification may have presented the method and/orprocess of the present invention as a particular sequence of steps.However, to the extent that the method or process does not rely on theparticular order of steps set forth herein, the method or process shouldnot be limited to the particular sequence of steps described. As one ofordinary skill in the art would appreciate, other sequences of steps maybe possible. Therefore, the particular order of the steps set forth inthe specification should not be construed as limitations on the claims.In addition, the claims directed to the method and/or process of thepresent invention should not be limited to the performance of theirsteps in the order written, and one skilled in the art can readilyappreciate that the sequences may be varied and still remain within thespirit and scope of the present invention.

1. A process for immobilizing high alkaline wastes in glass which achieves a high concentration of waste constituents (waste loading) comprising: combining a waste stream having one or more of radionuclides, hazardous elements, and hazardous components with glass-forming components in proportion to achieve a mixture capable of forming a high alkaline silicate-based glass consisting essentially of about 1.6 to about 2.2 parts in weight percent of a combination of monovalent cation oxides (R₂o) and divalent cation oxides (RO), about 1 part in weight percent trivalent cation oxides (R₂O₃), and about 2 to about 3 parts in weight percent of a combination of tetravalent cation oxides (RO₂) and pentavalent cation oxides (R₂O₅), wherein Na₂O is present in an amount greater than 23 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent; melting the mixture to form a melted glass with integrated waste; and solidifying the melted glass with integrated waste by cooling to form said high alkaline silicate-based glass.
 2. The process of claim 1, wherein said melting step is performed at temperatures up to about 1150 degrees Celsius.
 3. The silicate-based glass produced by the process of claim 1, wherein the ratio between the rock-forming components of the glass formed, approximates the ratio between the main components of natural high alkaline ultrabasic rock
 4. The silicate-based glass produced by the process of claim 1, wherein the rock-forming components of the said silicate-based glass consisting essentially of: about 1.6 to about 2.2 parts in weight percent of a combination of monovalent cation oxides (R₂O) and divalent cation oxides (RO); about 1 part in weight percent of trivalent cation oxides (R₂O₃); about 2 to about 3 parts in weight percent of a combination of tetravalent cation oxides (RO₂) and pentavalent cation oxides (R₂O₅); and wherein Na₂O is present in an amount greater than 23 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent.
 5. The silicate-based glass produced by the process of claim 1, wherein the rock-forming components of the silicate-based glass consisting essentially of: about 1.6 to about 2.2 parts in weight percent of a combination of monovalent cation oxides (R₂O), including alkaline oxides, and divalent cation oxides (RO), including alkaline earth oxides; about 1 part in weight percent of trivalent cation oxides (R₂O₃), including aluminum and ferric oxide; about 2 to about 3 parts in weight percent of a combination of tetravalent cation oxides (RO₂), including silicon, zirconium and titanium, and pentavalent cation oxides (R₂O₅), including and phosphorus oxide; and wherein Na₂O is present in an amount greater than 23 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent.
 6. The silicate-based glass produced by the process of claim 1, wherein the silicate-based glass has a viscosity of 20 to 100 poise at a temperature of about 1150 degrees Celsius.
 7. The silicate-based glass produced by the process of claim 1, wherein the silicate-based glass has specific electrical conductivity ranging between about 0.1 Ω⁻¹ cm⁻¹ to about 0.7 Ω⁻¹ cm⁻¹ at a temperature of about 1150 degrees Celsius, that is acceptable for processing in vitrification melters.
 8. The silicate-based glass produced by the process of claim 1, wherein the silicate-based glass meets the Vapor Hydration Test (VHT) requirements of less than about 50 grams per square meter per day, thus meeting current U.S. waste form acceptance criteria.
 9. The silicate-based glass produced by the process of claim 1, wherein the silicate-based glass meets the Product Consistency Test (PCT) requirements of less than about 2 grams per square meter, as defined in the American Society for Testing and Materials (ASTM) C 1285, thus meeting current U.S. waste form acceptance criteria.
 10. The silicate-based glass produced by the process of claim 1, wherein the U.S. Environmental Protection Agency's (EPA) Toxicity Characteristic Leach Test Procedure (TCLP) (SW-846 Method 1311) is performed and the silicate-based glass meets the U.S. EPA Universal Treatment Standard (UTS) for all of the analytes listed, thus meeting current U.S. waste form acceptance criteria.
 11. A process for immobilizing wastes comprising: combining a waste stream having one or more of radionuclides, hazardous elements, and hazardous components with glass-forming components in proportion to achieve a mixture capable of forming a high alkaline silicate-based glass consisting essentially of about 1.6 to about 2.2 parts in weight percent of a combination of monovalent cation oxides (R₂O) and divalent cation oxides (RO), including alkaline oxides and alkaline earth oxides, about 1 part in weight percent trivalent cation oxides (R₂O₃), including alumina and ferric oxide, and about 2 to about 3 parts in weight percent of a combination of tetravalent cation oxides (RO₂) and pentavalent cation oxides (R₂O₅), including silica, zirconia, titania, and phosphoric oxide, wherein Na₂O is present in an amount greater than 23 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent; melting the mixture to form a melted glass with integrated waste; and solidifying the melted glass with integrated waste by cooling to form said high alkaline silicate-based glass.
 12. The process of claim 11, wherein said melting step is performed at temperatures up to about 1150 degrees Celsius.
 13. The silicate-based glass produced by the process of claim 11, wherein the ratio between the rock-forming components of the glass formed, approximates the ratio between the main components of natural high alkaline ultrabasic rock
 14. The silicate-based glass produced by the process of claim 11, wherein the rock-forming components of the said silicate-based glass consisting essentially of: about 1.6 to about 2.2 parts in weight percent of a combination of monovalent cation oxides (R₂O) and divalent cation oxides (RO); about 1 part in weight percent of trivalent cation oxides (R₂O₃); about 2 to about 3 parts in weight percent of a combination of tetravalent cation oxides (RO₂) and pentavalent cation oxides (R₂O₅); and wherein Na₂O is present in an amount greater than 23 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent.
 15. The silicate-based glass produced by the process of claim 11, wherein the rock-forming components of the silicate-based glass consisting essentially of: about 1.6 to about 2.2 parts in weight percent of a combination of monovalent cation oxides (R₂O), including alkaline oxides, and divalent cation oxides (RO), including alkaline earth oxides; about 1 part in weight percent of trivalent cation oxides (R₂O₃), including aluminum and ferric oxide; about 2 to about 3 parts in weight percent of a combination of tetravalent cation oxides (RO₂), including silicon, zirconium and titanium, and pentavalent cation oxides (R₂O₅), including and phosphorus oxide; and wherein Na₂O is present in an amount greater than 23 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent.
 16. The silicate-based glass produced by the process of claim 11, wherein the silicate-based glass has a viscosity of 20 to 100 poise at a temperature of about 1150 degrees Celsius.
 17. The silicate-based glass produced by the process of claim 11, wherein the silicate-based glass has specific electrical conductivity ranging between about 0.1 Ω⁻¹ cm⁻¹ to about 0.7 Ω⁻¹ cm⁻¹ at a temperature of about 1150 degrees Celsius, that is acceptable for processing in vitrification melters.
 18. The silicate-based glass produced by the process of claim 11, wherein the silicate-based glass meets the Vapor Hydration Test (VHT) requirements of less than about 50 grams per square meter per day, thus meeting current U.S. waste form acceptance criteria.
 19. The silicate-based glass produced by the process of claim 11, wherein the silicate-based glass meets the Product Consistency Test (PCT) requirements of less than about 2 grams per square meter, as defined in the American Society for Testing and Materials (ASTM) C 1285, thus meeting current U.S. waste form acceptance criteria.
 20. The silicate-based glass produced by the process of claim 11, wherein the U.S. Environmental Protection Agency's (EPA) Toxicity Characteristic Leach Test Procedure (TCLP) (SW-846 Method 1311) is performed and the silicate-based glass meets the U.S. EPA Universal Treatment Standard (UTS) for all of the analytes listed, thus meeting current U.S. waste form acceptance criteria.
 21. A silicate-based glass consisting essentially of: about 1.6 to about 2.2 parts in weight percent of a combination of monovalent cation oxides (R₂O) and divalent cation oxides (RO); about 1 part in weight percent of trivalent cation oxides (R₂O₃); about 1 to about 2 parts in weight percent of a combination of tetravalent cation oxides (RO₂) and pentavalent cation oxides (R₂O₅); and wherein Na₂O is present in an amount greater than 23 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent.
 22. The silicate-based glass of claim 21, wherein the ratio between the rock-forming components of the glass formed, approximates the ratio between the main components of natural high alkaline ultrabasic rock.
 23. The silicate-based glass of claim 22, wherein the rock-forming components of the said silicate-based glass consisting essentially of: about 1.6 to about 2.2 parts in weight percent of a combination of monovalent cation oxides (R₂O) and divalent cation oxides (RO); about 1 part in weight percent of trivalent cation oxides (R₂O₃); about 2 to about 3 parts in weight percent of a combination of tetravalent cation oxides (RO₂) and pentavalent cation oxides (R₂O₅); and wherein Na₂O is present in an amount greater than 23 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent.
 24. The silicate-based glass of claim 22, wherein the rock-forming components of the silicate-based glass consisting essentially of: about 1.6 to about 2.2 parts in weight percent of a combination of monovalent cation oxides (R₂O), including alkaline oxides, and divalent cation oxides (RO), including alkaline earth oxides; about 1 part in weight percent of trivalent cation oxides (R₂O₃), including aluminum and ferric oxide; about 2 to about 3 parts in weight percent of a combination of tetravalent cation oxides (RO₂), including silicon, zirconium and titanium, and pentavalent cation oxides (R₂O₅), including and phosphorus oxide; and wherein Na₂O is present in an amount greater than 23 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent.
 25. The silicate-based glass of claim 21, wherein the silicate-based glass has a viscosity of 20 to 100 poise at a temperature of about 1150 degrees Celsius, that is acceptable for processing in vitrification melters.
 26. The silicate-based glass of claim 21, wherein the silicate-based glass has specific electrical conductivity ranging between about 0.1 Ω⁻¹ cm⁻¹ to about 0.7 Ω⁻¹ cm⁻¹ at a temperature of about 1150 degrees Celsius, that is acceptable for processing in vitrification melters.
 27. The silicate-based glass of claim 21, wherein the silicate-based glass meets the Vapor Hydration Test (VHT) requirements of less than about 50 grams per square meter per day, thus meeting current U.S. waste form acceptance criteria.
 28. The silicate-based glass of claim 21, wherein the silicate-based glass meets the Product Consistency Test (PCT) requirements of less than about 2 grams per square meter, as defined in the American Society for Testing and Materials (ASTM) C 1285, thus meeting current U.S. waste form acceptance criteria.
 29. The silicate-based glass of claim 21, wherein the U.S. Environmental Protection Agency's (EPA) Toxicity Characteristic Leach Test Procedure (TCLP) (SW-846 Method 1311) is performed and the silicate-based glass meets the U.S. EPA Universal Treatment Standard (UTS) for all of the analytes listed, thus meeting current U.S. waste form acceptance criteria.
 30. A silicate-based glass consisting essentially of: about 1.6 to about 2.2 parts in weight percent of a combination of monovalent cation oxides (R₂O), including alkaline oxides, and divalent cation oxides (RO), including alkaline earth oxides; about 1 part in weight percent of trivalent cation oxides (R₂O₃), including aluminum and ferric oxide; about 1 to about 2 parts in weight percent of a combination of tetravalent cation oxides (RO₂), including silicon, zirconium and titanium, and pentavalent cation oxides (R₂O₅), including phosphorus oxide; and wherein Na₂O is present in an amount greater than 23 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent.
 31. The silicate-based glass of claim 30, wherein the ratio between the rock-forming components of the glass formed, approximates the ratio between the main components of natural high alkaline ultrabasic rock.
 32. The silicate-based glass of claim 31, wherein the rock-forming components of the said silicate-based glass consisting essentially of: about 1.6 to about 2.2 parts in weight percent of a combination of monovalent cation oxides (R₂O) and divalent cation oxides (RO); about 1 part in weight percent of trivalent cation oxides (R₂O₃); about 2 to about 3 parts in weight percent of a combination of tetravalent cation oxides (RO₂) and pentavalent cation oxides (R₂O₅); and wherein Na₂O is present in an amount greater than 23 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent.
 33. The silicate-based glass of claim 31, wherein the rock-forming components of the silicate-based glass consisting essentially of: about 1.6 to about 2.2 parts in weight percent of a combination of monovalent cation oxides (R₂O), including alkaline oxides, and divalent cation oxides (RO), including alkaline earth oxides; about 1 part in weight percent of trivalent cation oxides (R₂O₃), including aluminum and ferric oxide; about 2 to about 3 parts in weight percent of a combination of tetravalent cation oxides (RO₂), including silicon, zirconium and titanium, and pentavalent cation oxides (R₂O₅), including and phosphorus oxide; and wherein Na₂O is present in an amount greater than 23 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent.
 34. The silicate-based glass of claim 30, wherein the silicate-based glass has a viscosity of 20 to 100 poise at a temperature of about 1150 degrees Celsius, that is acceptable for processing in vitrification melters.
 35. The silicate-based glass of claim 30, wherein the silicate-based glass has specific electrical conductivity ranging between about 0.1 Ω⁻¹ cm⁻, to about 0.7 Ω⁻¹ cm⁻¹ at a temperature of about 1150 degrees Celsius, that is acceptable for processing in vitrification melters.
 36. The silicate-based glass of claim 30, wherein the silicate-based glass meets the Vapor Hydration Test (VHT) requirements of less than about 50 grams per square meter per day, thus meeting current U.S. waste form acceptance criteria.
 37. The silicate-based glass of claim 30, wherein the silicate-based glass meets the Product Consistency Test (PCT) requirements of less than about 2 grams per square meter, as defined in the American Society for Testing and Materials (ASTM) C 1285, thus meeting current U.S. waste form acceptance criteria.
 38. The silicate-based glass of claim 30, wherein the U.S. Environmental Protection Agency's (EPA) Toxicity Characteristic Leach Test Procedure (TCLP) (SW-846 Method 1311) is performed and the silicate-based glass meets the U.S. EPA Universal Treatment Standard (UTS) for all of the analytes listed, thus meeting current U.S. waste form acceptance criteria.
 39. A process for immobilizing high alkaline wastes in glass which achieves a high concentration of waste constituents (waste loading) comprising: combining a waste stream having one or more of radionuclides, hazardous elements, and hazardous components with glass-forming components in proportion to achieve a mixture capable of forming a high alkaline silicate-based glass consisting in weight percent essentially of about 1.6 to about 2.2 parts of a combination of monovalent cation oxides (R₂O) and divalent cation oxides (RO), about 1 part trivalent cation oxides (R₂O₃), and about 2 to about 3 parts of a combination of tetravalent cation oxides (RO₂) and pentavalent cation oxides (R₂O₅), wherein Na₂O is present in an amount greater than 23 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent; melting the mixture to form a melted glass with integrated waste; solidifying the melted glass with integrated waste by cooling to form said high alkaline silicate-based glass; insuring that the melted glass with integrated waste meets the Vapor Hydration Test (VHT) requirements of less than about 50 grams per square meter per day; insuring that the melted glass with integrated waste meets the Product Consistency Test (PCT) requirements of less than about 2 grams per square meter, as defined in the American Society for Testing and Materials (ASTM) C 1285; and wherein the U.S. Environmental Protection Agency's (EPA) Toxicity Characteristic Leach Test Procedure (TCLP) (SW-846 Method 1311) is performed and the silicate-based glass meets the U.S. EPA Universal Treatment Standard (UTS) for all of the analytes listed, thus meeting current U.S. waste form acceptance criteria.
 40. A silicate-based glass consisting essentially of: about 1.6 to about 2.2 parts in weight percent of a combination of monovalent cation oxides (R₂O) and divalent cation oxides (RO); about 1 part in weight percent of trivalent cation oxides (R₂O₃); about 1 to about 2 parts in weight percent of a combination of tetravalent cation oxides (RO₂) and pentavalent cation oxides (R₂O₅); wherein Na₂O is present in an amount greater than 23 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent; insuring that the melted glass with integrated waste meets the Vapor Hydration Test (VHT) requirements of less than about 50 grams per square meter per day; insuring that the melted glass with integrated waste meets the Product Consistency Test (PCT) requirements of less than about 2 grams per square meter, as defined in the American Society for Testing and Materials (ASTM) C 1285; and wherein the U.S. Environmental Protection Agency's (EPA) Toxicity Characteristic Leach Test Procedure (TCLP) (SW-846 Method 1311) is performed and the silicate-based glass meets the U.S. EPA Universal Treatment Standard (UTS) for all of the analytes listed, thus meeting current U.S. waste form acceptance criteria.
 41. A process for immobilizing high alkaline wastes in glass which achieves a high concentration of waste constituents (waste loading) comprising: combining a waste stream having one or more of radionuclides, hazardous elements, and hazardous components with glass-forming components in proportion to achieve a mixture capable of forming a high alkaline silicate-based glass consisting in weight percent essentially of about 1.6 to about 2.2 parts of a combination of monovalent cation oxides (R₂O) and divalent cation oxides (RO), about 1 part trivalent cation oxides (R₂O₃), and about 2 to about 3 parts of a combination of tetravalent cation oxides (RO₂) and pentavalent cation oxides (R₂O₅), wherein Na₂O is present in an amount greater than 24 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent; melting the mixture to form a melted glass with integrated waste; and solidifying the melted glass with integrated waste by cooling to form said high alkaline silicate-based glass.
 42. The silicate-based glass of claims 41, wherein Na₂O is present in an amount greater than 25 weight percent.
 43. The silicate-based glass of claims 41, wherein Na₂O is present in an amount greater than 26 weight percent.
 44. The silicate-based glass of claims 41, wherein Na₂O is present in an amount greater than 27 weight percent.
 45. The silicate-based glass of claims 41, wherein Na₂O is present in an amount greater than 28 weight percent.
 46. The silicate-based glass of any of claims 41, wherein Al₂O₃ is present in an amount greater than about 15 weight percent and less than about 20 weight percent.
 47. A silicate-based glass consisting essentially of: about 1.6 to about 2.2 parts in weight percent of a combination of monovalent cation oxides (R₂O) and divalent cation oxides (RO); about 1 part in weight percent of trivalent cation oxides (R₂O₃); about 1 to about 2 parts in weight percent of a combination of tetravalent cation oxides (RO₂) and pentavalent cation oxides (R₂O₅); and wherein Na₂O is present in an amount greater than 24 weight percent, Al₂O₃ is present in an amount greater than about 13 weight percent and less than about 20 weight percent, SiO₂ is present in an amount greater than about 30 weight percent and less than about 48 weight percent, and B₂O₃ and other flux components are present in a total amount greater than about 9 weight percent and less than about 15 weight percent.
 48. The silicate-based glass of claims 47, wherein Na₂O is present in an amount greater than 25 weight percent.
 49. The silicate-based glass of claims 47, wherein Na₂O is present in an amount greater than 26 weight percent.
 50. The silicate-based glass of claims 47, wherein Na₂O is present in an amount greater than 27 weight percent.
 51. The silicate-based glass of claims 47, wherein Na₂O is present in an amount greater than 28 weight percent.
 52. The silicate-based glass of any of claims 47, wherein Al₂O₃ is present in an amount greater than about 15 weight percent and less than about 20 weight percent. 